Version 4
SHEET 1 880 680
WIRE 240 128 224 128
WIRE 192 144 176 144
WIRE 304 160 256 160
WIRE 320 160 304 160
WIRE 464 160 400 160
WIRE -64 176 -96 176
WIRE 48 176 16 176
WIRE 144 176 112 176
WIRE 192 176 144 176
WIRE 464 176 464 160
WIRE -96 192 -96 176
WIRE 48 192 48 176
WIRE 240 192 224 192
WIRE 144 208 144 176
WIRE 432 208 336 208
WIRE -160 224 -176 224
WIRE -96 224 -96 192
WIRE 176 224 176 144
WIRE 208 224 176 224
WIRE 304 224 304 160
WIRE 304 224 288 224
WIRE -176 240 -176 224
WIRE 176 256 176 224
WIRE 320 256 176 256
WIRE 464 256 464 240
WIRE 176 272 176 256
WIRE -128 288 -144 288
WIRE -128 320 -128 288
WIRE -96 320 -96 304
WIRE -96 320 -128 320
WIRE 272 320 256 320
WIRE 320 336 320 256
WIRE 320 336 304 336
WIRE -176 352 -176 336
WIRE -160 352 -176 352
WIRE 144 352 144 288
WIRE 176 352 176 336
WIRE 176 352 144 352
WIRE 240 352 176 352
WIRE -96 368 -96 320
WIRE 336 368 336 208
WIRE 336 368 304 368
WIRE 464 368 464 336
WIRE 272 384 256 384
FLAG 240 192 V-
FLAG 240 128 V+
FLAG 256 384 V-
FLAG 256 320 V+
FLAG 464 368 0
FLAG -96 368 0
FLAG -160 224 V+
IOPIN -160 224 Out
FLAG -160 352 V-
IOPIN -160 352 Out
FLAG 48 192 Out
IOPIN 48 192 Out
FLAG -96 192 In
SYMBOL Robertugo\\opamp5 224 96 R0
WINDOW 0 -28 65 Left 0
WINDOW 38 31 50 Left 0
SYMATTR InstName U1
SYMATTR SpiceModel level2
SYMBOL res 32 160 R90
WINDOW 0 15 110 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R1
SYMATTR Value 4k7
SYMBOL cap 112 160 R90
WINDOW 0 16 55 VBottom 0
WINDOW 3 -12 5 VTop 0
SYMATTR InstName C1
SYMATTR Value 68n
SYMBOL res 128 192 R0
WINDOW 0 -32 34 Left 0
WINDOW 3 -45 63 Left 0
SYMATTR InstName R2
SYMATTR Value 22k
SYMBOL res 304 208 R90
WINDOW 0 16 106 VBottom 0
WINDOW 3 -12 22 VTop 0
SYMATTR InstName R3
SYMATTR Value 22k
SYMBOL Robertugo\\opamp5 272 288 M0
WINDOW 0 -28 63 Left 0
WINDOW 38 -44 14 Left 0
SYMATTR InstName U2
SYMATTR SpiceModel level2
SYMBOL res 448 240 R0
WINDOW 0 -39 59 Left 0
WINDOW 3 -43 88 Left 0
SYMATTR InstName R4
SYMATTR Value 10k
SYMBOL res 416 144 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 -13 18 VTop 0
SYMATTR InstName R5
SYMATTR Value 10k
SYMBOL Robertugo\\Pote 448 144 R0
WINDOW 0 -42 47 Left 0
WINDOW 3 -61 99 Left 0
WINDOW 123 -48 124 Center 0
SYMATTR InstName P1
SYMATTR Value Rt=5K
SYMATTR Value2 Set={cur}
SYMBOL voltage -96 208 R0
WINDOW 0 -15 58 Left 0
WINDOW 3 40 72 Left 0
WINDOW 123 40 45 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value SINE(0 1 50)
SYMATTR Value2 AC 1
SYMBOL Miscel\\v+&- -176 272 R0
SYMATTR InstName U3
SYMBOL cap 160 272 R0
WINDOW 0 24 4 Left 0
WINDOW 3 59 4 Left 0
SYMATTR InstName C2
SYMATTR Value 300n
TEXT -68 318 Left 0 !.ac dec 100 1 10k
TEXT -72 376 Left 0 !.step param cur 0 1 0.25